Mercury – Water Pump Impeller Repair Kit | For 8 & 9.9HP FourStroke Outboards | 803748K01

Overview

A dependable cooling system keeps your outboard running strong, and the Mercury Marine 803748K01 Water Pump Impeller Repair Kit makes sure it stays that way. Designed for Mercury 8HP and 9.9HP EFI and carbureted FourStroke outboards (model year 2005 and newer), this kit includes all the key parts needed to restore proper water flow and cooling performance. It’s a straightforward, OEM-quality repair that ensures your motor runs cool, smooth, and reliable season after season.

Key Features

• Purpose: Restores cooling performance by replacing worn water pump components.
• Compatibility: For Mercury 8HP and 9.9HP FourStroke EFI and carbureted outboards with standard gearcases (2005 and newer).
• Complete Kit: 6-piece set includes impeller, gaskets, roller pin, grommet, plate, and water guide tube.
• Performance: Maintains proper water pressure and flow to prevent overheating.
• Ease of Use: Direct OEM fit for quick installation with standard tools.

Engine & Boat Compatibility

• Mercury 8HP and 9.9HP FourStroke EFI and carbureted outboards
• Model year 2005 and newer, standard gearcase

Performance & Real-World Benefits

The 803748K01 impeller repair kit keeps your cooling system working the way it should by ensuring steady water flow through your engine. Over time, impellers and gaskets wear down, which can lead to overheating or reduced performance. Replacing them with genuine Mercury parts restores your outboard’s efficiency and peace of mind.

This OEM kit has everything you need to service your pump in one box — no hunting for extra parts. It’s designed to fit perfectly and perform flawlessly, giving you the same reliability your engine had when it was new.

Why Choose Mercury OEM

The Mercury 803748K01 is a genuine Mercury Marine kit, built to the same standards as the parts that came on your engine. Aftermarket kits can use lower-grade materials that don’t hold up to marine conditions or fit precisely.

Mercury’s OEM components are tested for long-term durability and water resistance, ensuring they’ll keep your outboard running cool under heavy use. It’s the same quality trusted by Mercury technicians and service centers worldwide.

FAQ

Q1: What engines does this kit fit?
It’s for Mercury 8HP and 9.9HP FourStroke EFI and carbureted outboards, model year 2005 and newer.

Q2: What’s included in the kit?
A 6-piece set with impeller, gaskets, roller pin, grommet, plate, and water guide tube.

Q3: Why replace the impeller?
Worn impellers can reduce water flow, causing overheating and potential engine damage.

Q4: Is this a complete repair kit?
Yes — it includes all key components for a full water pump service.

Q5: Why OEM instead of aftermarket?
OEM parts ensure exact fit, proper flow, and proven durability, while aftermarket versions often wear out faster.